This invention relates to single crystal dendritic webs and more particularly to a susceptor lid which enhances the thermal environment of the web adjacent the lid.
Forming a ribbon crystal by dendritic web growth is controlled by crystallography and surface tension force rather than the shape defining dyes. Ribbons of indium antimonide, gallium arsenide, germanium and silicon and other crystalline materials may be produced by providing a liquid pool of the crystalline material and placing a dendritic seed of the crystalline material which is supercooled a few degrees into the molten pool and as the temperature in the pool falls, the seed first spreads laterally to form a button. The seed is then raised causing two secondary dendritic boundaries to propagate from each end of the button and extend into the pool The button and dendritics form a frame which support a liquid film of the molten material which crystallizes to form a web generally 0.1 to 0.2 mm. thick. The web and bordering dendritics can theoretically be propagated indefinitely be replenishing the liquid pool as the dendritic ribbon is pulled from the pool. The ribbon width and growth velocity are determined by the thermal conditions in the melted pool and the environment adjacent the emerging dendritic ribbon. For a more detailed description of the dendritic web formation, reference may be made to an article by R. G. Seidensticker (one of the inventors) and R. H. Hopkins, entitled, "Silicon Ribbon Growth by the Dendritic Web Process", publishes in the Journal of Crystal Growth, Vol. 50, 1980, pages 221 to 235.